Three projects of this program involve the study of the consequences of gain or loss of function of specific genes (BCL8; BCL6; LRF1) in transgenic mice. The development of these projects requires the expert and efficient analysis of large number of mice using various diagnostic procedures, including macroscopic anatomic examination, microscopic histology, immunohistochemical analysis using specific antibodies, and cytofluorimetric measurements of hematopoietic cell subpopulations. The general aim of this Core is to provide a facility in which this complex set of analysis will be optimized for: i) standardization and quality control; ii) efficiency; iii) cost reduction; iv) expert integration and interpretation of the results. The facility will be directed by an experienced pathologist with special expertise in experimental and clinical hematology.